The protein collagen in the dermis or the second layer of the skin provides a strong and healthy skin. Vitamin C has a crucial role to play in collagen synthesis. Collagen synthesis is induced and supported by Vitamin C. Vitamin C being highly water soluble, hence, its availability at the site of collagen synthesis is restricted since the parts of the skin are lipophilic and therefore Vitamin C is easily eliminated from the body. During ageing collagen synthesis is retarded resulting in the falling of the strength and support to the skin. This results in wrinkling and sagging of the skin. Hence it is necessary to devise methods for inducing collagen synthesis vigorously by providing adequate concentrations of Vitamin C at the dermis. Any amount of Vitamin C ingested through oral or other conventional routes cannot provide adequate concentrations of Vitamin C at the site of collagen synthesis and it is now well recognized that providing Vitamin C across the skin structure through topical application is the best way to achieve this. However due to the high water solubility of Vitamin C, its transportation across lipophilic skin membranes is also slow.
The presence of radical oxygen converts dihydroxyphenylalanine (DOPA) to DOPA-quinone, which is further converted to melanin. Melanin is dark brown and it further polymerizes to black melanin pigment and these are responsible for the color of brown and black skins. It has been recognized that the best way to prevent formation of these melanin pigments is to inhibit the oxidation of DOPA to DOPA-Quinone and the conversion further of the latter to melanin pigments. Two agents that inhibit melanin pigment formation are Vitamin C and hydrogen ions. Hydrogen ions in the presence of reducing agents like Vitamin C can inhibit this melanin synthesis and also reverse it, resulting in the whitening of skin.
One of the major causes of melanin pigmentation of the skin is exposure to UV light present in the sun's radiation and various artificial lighting methods. There are ways to protect the skin from UV or actinic radiation by providing applications containing molecules that absorb UV light.
Vitamin C like activity is not confined to ascorbic acid. The Vitamin C bioactivity including anti scorbutic activity, promotion of collagen synthesis and various anti oxidant and free radical scavenging properties, arise from the specific chemical structural feature 1-oxo-2-ene-2, 3-diol, which is referred to as aci-reductones or simply reductones. There are many such reductones in nature especially in fruits and one such fruit containing reductones is the Indian gooseberry also known as Amla in India whose scientific nomenclature is Emblica officinalis Gaertn.
The constituents of the Indian gooseberry dry extract described by Ghosal in his patent U.S. Pat. No. 6,235,721 as ‘CAPROS’ is said to contain the following components and the proportion indicated: An antioxidant blend consisting of, by weight:
Emblicanins A and B, that is,
the gallic acid-ellagic acid esters of 2-keto-gluconodelta lactone: 35-55%;
2,3-di-o-galloyl 4,6-S-hexahydroxydiphenoylgluconic acid (Punigluconin): 4-15%;
2,3,4,6,-bishexahydroxydiphenoyl glucose (Pedunculagin): 10 to 20%, and
about 5 to 15% of 3′,4′,5,7-tetrahydroxy flavone-3-O-rhamnoglucoside (Rutin);
Tannoids of gallic/ellagic acids 10-30%;
Gallic acid 0-5%; and,
Ellagic acid 0-5%.
Chaudhari et al in their U.S. Pat. No. 6,649,150 on skin lightening or whitening compositions have described the need to restrict the presence of flavonoids like rutin which are yellow colored and not desirable in a skin whitening composition based on the same Indian gooseberry extract. Chaudhuri et al describe a method to select geographically or maturity levels of the fruit or by removing by chromatography the undesirable flavonoid pigment to the minimum that is, below 1% or better, 0.1% or more preferably 0.01%. They have also described the flavonoids to have strong UV absorption in the wavelength region of 350 nanometers.
The composition Chaudhuri et al is reported to have the following content:
Emblicanin A: 20-35%;
Emblicanin B 10-20%;
Pedunculagin 15-30%;
Punigluconin 3-12%; and,
Flavonoids less than 1%.